xev does not recognize button

[alexandermeyers at keemail.me]

Hello,
I use uhidd (installed by pkg) to get a Contour Rollermouse red working, which is a kind of mouse replacement. All buttons except one are working fine. There is one button which is not recognized as a mouse button and is not visible in xev. I use 11.1-RELEASE-p4.

It seems that the uhidd creates two devices for the Rollermouse
1. mouse (can be used as sysmouse); all functions are working,
2. uvhid1; the single button which is recognized as uvhidx is not working in xev.

The options in my rc.conf are the following
uhidd_flags="-mh"
uhidd_enable="YES"

When I start uhhid via a shell in vebose mode, the button which xev does not recognize shows the following output:

ugen0.2[0]-> received data(16): 03 00 00 00 00 00 02 00 00 00 00 00 00 00 00 00 
hid_appcol_recv_data: len(16) 0x03 0x00 0x00 0x00 0x00 0x00 0x02 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x00
ugen0.2[0]-> uvhid1 received data: 3 0 0 0 0 0 2 0 0 0 0 0 0 0 0 0

A button which is recognized by xev shows the following ouput:
ugen0.2[0]-> received data(16): 01 00 00 00 00 00 00 00 02 00 01 00 00 00 00 00 
hid_appcol_recv_data: len(16) 0x01 0x00 0x00 0x00 0x00 0x00 0x00 0x00 0x02 0x00 0x01 0x00 0x00 0x00 0x00 0x00
ugen0.2[0]-> mouse received data: dx(0) dy(0) dw(0) dt(0) btn(0)

I would like to use the single button which is not recognized by xev as mouse 1 in xorg but I don't know how. Without uhidd (respectively with uhid.ko only) all buttons are recognized by xev but when pressing i. e. mouse 2, mouse 1 is also activated. This applies to all buttons except the one which is seen by xev when using uhidd.

Maybe anyone has some tips for me. 

Thanks a lot and best regards
Alex